Electrocardiographs which visually display the heart activity of living subjects are well recongized to be of great value in the diagnosis and treatment of medical patients. Instruments of this type are also useful for a number of other purposes such as in the monitoring of cardiac activity in persons undergoing exercise training or for the display of an ECG for educational purposes.
The conventional electrocardiograph is a complex, costly and usually bulky assembly which must be operated by professional medical personnel or highly skilled technicians. Consequently, usage of such equipment has more or less been restricted to hospitals, medical clinics, and medicial emergency vehicles. Compact and economical cardiac monitors have been developed but in general these produce only an audible signal or otherwise do not provide the type of data that is available from an ECG.
A more compact and economical cardiac monitor would be highly advantageous not only in medical facilities but also for usage elsewhere. Such a device would for example, enable persons with cardiovascular problems to monitor their heart activity in their homes. Such apparatus should not require that the operator have specialized skills or undergo extensive training and should not expose the user to potential hazards such as electrical shock.
Instruments for obtaining electrodcardiograms include spaced apart electrodes which contact the persons skin in the thoracic region in order to sense the minute voltage changes which accompany heart activity. The sensed voltage changes are amplified and displayed on the screen of an oscilloscope and/or are applied to a chart recorder to printer type of readout device to provide the electrocardiogram. The sensed voltage signals have also heretofore been digitized and transmitted to a computer which may variously be programmed to detect abnormal activity, to determine average values for specific phases of the cyclic heart activity or to analyze the data in a variety of other ways.
Prior computer aided heart monitoring systems do not resolve the problems discussed above. The computer typically functions only as a permanent component of the electrocardiograph and is not used for any other purpose. Thus it further increases the cost and often the bulk of the heart activity monitoring installation. The prior computer aided systems, like older types of electrocardiograph, require highly trained operators.
The present invention is directed to overcoming one or more of the problems discussed above.